Contrast enhanced breast imaging techniques are able to provide functional information of breast lesions by using an intravenous contrast agent, usually iodine. Today, clinical diagnosis of contrast enhanced x-ray imaging images is often based on the qualitative assessment of contrast agent uptake and characterization of the morphology of the enhancing lesions.
According to a first prior art, which concerns classical contrast enhanced spectral mammography, it is known to inject a contrast agent which will propagate in the breast of a patient, to image the breast, to assess qualitatively enhancement of the contrast enhanced breast image to detect whether there is or not an identified risk of a breast lesion, for example of a breast cancer. A limitation of this first prior art is that it allows only for a qualitative assessment of the enhancement of the contrast enhanced breast image. In some cases, this qualitative assessment may lead to insufficiently precise risk assessment or even to erroneous diagnostic of the lesion risk of the patient breast.
According to a second prior art, for example described in “Jong et al. Contrast-enhanced Digital Mammography: Initial Clinical Experience, Radiology 2003”, it is known a phantom image made with a contrast agent insert and used as a reference to try and quantify another contrast enhanced breast image performed later on. A drawback of this second prior art lies in the fact that a phantom image cannot reproduce accurately all the clinical imaging conditions, among which specific breast thickness, specific breast area covering the detector of the imaging system, specific glandularity of the breast, specific effective spectrum and scatter conditions. Failing to reproduce accurately those clinical imaging conditions can lead to imprecise or even to inaccurate quantification of the enhancement of the contrast enhanced breast image.
According to a third prior art, for example described in U.S. Pat. No. 5,335,260, it is known a bone density quantification method using a reference imaged simultaneously with the body of a patient. Such third prior art does not use any contrast agent injection nor does it concern breast imaging.
According to embodiments of the invention, it is noticed that none of those prior art documents allows for an accurate and precise quantification of the enhancement of the contrast enhanced breast image to more accurately evaluate breast lesion risk and or to more accurately follow up an identified breast lesion.